Holy grail replaceable battery power bank/phone/laptop charger ?

I was searching for a power bank that could power a soldering iron and I found this:


several sellers on aliexpress have it
https://www.aliexpress.com/item/3-3...ger-For-19V-Laptop-5V-iphone/32833114711.html

it is able to output dc at 12V - 21V, enough to power a laptop!
and the batteries are easily replaceable, so if one cell dies, you can just swap it with a new one.
Or stick in there high drain cells and use it as a jump starter for your car?
What do you guys think?
The main turn off for power banks right now is that they come with batteries and they are soldered, so you are stuck with whatever capacity and max current output they got

That's a good find. Get a cheap 16-24 volt power supply with 5.5*2.1-2.5mm plug to charge it and you're ready to go mobile. Good thing with these is you can use decent quality 18650's. Some power banks have tiny batteries in them.

And keep an eye out for DIY power banks like this that just do 5 volt USB. Got an 8-cell unit cheap, works good and it's a decent way to store cells.

I mentioned that Aili-119 here and on BLF a few times over the past few years, e.g. see here and see here for further discussion.